Fuel pump with pulsator



Jan. 13, 1959 REINERTSQN 2,868,135

FUEL PUMP WITH PULSATOR Filed Oct. 19. 1955 w j Z 2a 2 y Z; I Z 25 v if 1/ 2x IN VENT OR.

ATTORNEY 2,868,135 Patented Jan. 13, 1959 .86 .1 V FUELPUMP WITH PULSATOR Donald R. Reinertson, Flint, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application October 19, 1955, Serial No. 541,421

6. Claims. c1..103-1s0 Thisv invention relates to fuel pumps and more particularly to pumps of the diaphragm type utilized to 'supply fuel for internal combustion engines.

Pumps of the diaphragm type are used extensively in drawing fuel from tanks to the enginesof vehicles. Such 'a mechanism usually employs an arm or lever .means adapted to be'operated by the engine cam shaft for actuating a diaphragm against a biasing spring, the springserving to actuate the diaphragm during the fuel and outlet chambers by meansof a diaphragm. Such a device has been very elfective in its operation.

It has now been found that the, capacity of a pump having'pulsator chambers such as disclosed by the patentabove referred to may be increased appreciably by changing the relationship in position of the pulsator diaphragm means: with respect to the pump valves and ports and it is to'this improved pulsator type of fuel pump that the present invention is directed.

An object of the present invention is to provide a fuel pump with an improved pulsator arrangement for increasing the capacity and improving the uniformity in discharge of the pump.

A feature of the invention resides in a fuel pump having pulsator diaphragm means lying in intersecting planes. Another feature resides in a fuel pump having a pump body and recessed means with registering V- shaped contours and between which diaphragm means are interposed to define pulsator chambers.

These and other important features of the invention will now be described in detail in the specification and then pointed out more particularly in the appended claims.

In the drawings: Fig. 1 is a sectional elevational view of a fuel pump 1 in which features of the present invention are embodied;

Fig. 2 is a sectional view of a portion of the structure shown in Fig. 1 and taken along the line 2--2 in Fig. l; and

Fig. 3 is a perspective'view of recessed means or a cap shown in the assembly. of Fig. l.

Fig. l of the drawings depicts a pump body 10 having a threaded inlet 12 and a threaded outlet 14 communicating with inlet and outlet chambers 16 and 18 respectively. These chambers are separated by a vertical wall 20 which extends upwardly from a horizontal partition22 formed in the pump body. The partition sup- 2 portsan inlet check valve 24 and an outlet check valve 26 as is customary in such pumps.

Beneath-the chambers 16 and 18 and the partition 22 a pumping chamber 28 is defined by the pump body 1t). The valves 24 and 26 are of conventional construction and are adapted to control the flow of fuel from the chamber 16 into the pumping chamber 28 and then into the outlet chamber 18, as will be understood.

A pumping diaphragm 30 is provided with its margin clamped between a pump support body 32 and the peripheral bottom margin of the pump body 10. These parts are held together by means of screws 34. The central portion of the diaphragm 30 is clamped between two discs 36 and 38 which are held together on the upper endportion of a plunger 40. This plunger passes through the diaphragm 30 and the discs 36 and 38 and holds the latter with the aid of washers'42, 44 and 46,

t as well as the head 48 and a shoulder portion 50 formed on the plunger. A chamber 52 is defined by the body 32 and is adapted to accommodate a disc 54 and a helical spring 56. One end of the latter bears against the washer 46 and the other end bears against the disc 54. The spring serves to actuate the pumping diaphragm 3il as will further appear.

Connected to the lower end of the plunger 44) is one end of a lever 58. This lever is pivoted to a shaft 60 mounted in the sides of the lower body 32. A second lever 62 is also pivoted on the shaft 60 and is so arranged as to actuate lever 58. The action of the two levers 58 and 62 is assisted by a helical spring 64 interposed between a protuberance 66 on the lever 62 and a shoulder 67 formed within and upon the body '32. A curved surface 68 on the lever 62 is adapted to be held by the spring 64 in engagement with a cam 70 formed on the cam shaft 72. The cam shaft 72 is a part of the internal combustion engine to be served by the fuel pump. As is conventional in such pumps, the cam 70 rotates with the result that the levers 62 and 58 cooperate to move the plunger 40 downwardly against the compression of the spring 56 and upward motion of the plunger 40 is caused by the action of the spring 56 to bring about the pumping action of the diaphragm 30.

Details of the pump mechanism within the body 32 need not be further described herein as they are conventional, but it will be understood that fuel entering through port 12 into thechamber 16 is caused to flow downwardly through the check valve 24 into the chamber 28 when the pumping diaphragm 30 is flexed downwardly. As this occurs the valve 26 is closed. When 'the diaphragm 3tlis flexed upwardly, the valve 24 will close and the valve 26 will open causing a discharge of fuel, previously admitted to the chamber 28, to the chamber 18 and then from'the port 14.

The top of the pump body 10 is provided with recessed means or a cap which is affixed to the body 10 by means of two screws Y82 and 84. The recessed means is provided with a central and transverse web 86 with enlarged portions 88 and 90 bored to receive,

the two screws 84 and 82 respectively. The recessed means presents a V-shaped contour, as viewed from the side, and the construction is best visualized by consideration of Fig. 3 in the drawings. The cap 80 is so made that its V-shaped contour extends into the body 16 with the central web corresponding with and lying in the plane of the vertical wall 20 of the body 10. interposed between the body 10 and the recessed means 80 is a yieldable diaphragm 92 which closes off two pulsator chambers 94 and 96 which are recesses in the cap 80. When the parts are in assembly, as shown in Fig. l, the pulsator chambers 94 and 96 register with the chambers 16 and "18 by way 'of the valves 24 and 26 are such as to aid in the how of the fuel and increase the capacity of the pump substantially over that shown in the patent above referred to. It is also to be noted that the effective areas of the diaphragm 92 are larger than would be the case if they were parallel with the partition 22. It will be appreciated-that the increased capacity is taken advantage of by providing a portion of the pulsatordiaphragm at an inclined angle with the corresponding check valve.

The diaphragms 30 and 22 may be made from resin impregnated fibrous material as commonly used in pumps of this type. r

Not only does the action of the diaphragm 92 act to stabilize the flow of fuel through the pump as such devices have done heretofore in the past, but it enhances such stabilization and increases the'capacity of the pump appreciably as stated above and in some instances such increase in the nature of to percent.

It will be noted that the under surface on each half of the diaphragm 92 inclines away from a check valve 24 or 26 and towards the side of the port 12 or '14 away from the corresponding valve. This arrangement is essential in practicing the present invention. It is-to be noted also that the partition 22 bearing the two valves 24 and 26 extends in one plane. It is not feasible to cause the partition 22 to be V-shaped in section and to retain the diaphragm 92 in a flat form as an equivalent structure for, if such a structure were provided, the pumping chamber 28 would have an excessive capacity in the zone immediately beneath the wall and vapor lock in the pumping chamber and other difficulties of operation would be met with,

The drawings depict the pump with the recessed means respectively body and defining a pulsator chamber substantially in registry with each of said inlet and outlet chambers, diaphragm means interposed between said pump body and said recessed means and closing said pulsator chamber, said diaphragm means being so arranged as to present a yielding surface inclined away from one of said check valves to thepump body at the side of one of said ports away from said one check valve.

80 or cap located at the top but it is to be understood that the principles of thepresent invention still obtain even if the pump is installed with the cap down or to one side.

I claim:

1. A fuel pump having a pump body with a pump chamber partially defined by a pumping diaphragm and provided with inlet and outlet valves, chambers and ports, recessed means forming a plurality of pulsator chambers and fixed to said pump body, said valves having axes parallel with the axis of said pumping diaphragm, biplanar diaphragm means interposed between said pump body and said recessed means and closing said pulsator chambers, and at least part of said bi-planar diaphragm means being inclined away from one of said valves and extending to the pump body at one side of one of said ports.

2. A fuel pump having a pump body with inlet and outlet chambers controlled by check valves and defining a port leading from the exterior of said body to each of said chambers, said valves having seats lying in planes parallel to each other, recessed means fixed to said pump 3. A fuel pump having a pump body with a pump chamber partially defined by a pumping diaphragm and inlet and outlet chambers connected to the pump chamber by check valves, a port leading from each of said inlet and outlet chambers, said check valves being arranged in a partition of said body, said partition being substantially parallel with the axesof said ports-and extending in a plane parallel with the axis of said pumping diaphragm, recessed means fixed to said pump body and defining pulsator chambers, and diaphragm means interposed between said bodyand recessed means and presenting a surface inclined away from one of said valves to the pump body at the side of one of said ports away from said one valve.

4. A fuel pump having a pump body with a pump chamber and inlet and outlet chambers, a partition separating said pump chamber from the latter chambers and extending in one plane, pressure operated valves in said partition, a pumping diaphragm parallel with said plane and partially defining said pumping chamber, recessed means fixed to said pump body and defining pulsator chambers, and diaphragm means having portions extending to the periphery of said pump body and lying in intersecting planes and interposed between said body and said recessed means.

5. A fuel pump having a pump body defining a pump chamber and inlet and outlet chambers communicating with saidpump chamber by means of check valves, said check valves having their axes substantially parallel, a partition extending in one plane and supporting said check valves, recessed means fixed to said pump body and having pulsator chambers, each of said pulsator chambers cooperating with one of said inlet and outlet chambers, and a diaphragm having portions extending to the pump body periphery and lying in intersecting planes and interposed between said body and said recessed means partially to define said pulsator chambers.

6. A fuel pump having a pump body defining a pump chamber and inlet and outlet chambers, a partition separating said pump chamber from the latter chambers, a port leading from each of said inlet and outlet chambers, recessed means fixed to said pump body and having pulsator chambers corresponding with said inlet and outlet chambers, said pump body and recessed means having registering V-shaped contours whereby said recessed means extends into said pump body, and diaphragm means interposed between said body and said recessed means partially to define said pulsator chambers.

References (lifted in the file of this patent UNITED STATES PATENTS Coffey Jan. 29, 1957 

